Recent genome-wide analysis of alternative splicing indicates that a large portion of human genes, probably more than half, have alternative splice forms. Alternative splicing provides the cell with a mechanism to generate multiple gene products from the same transcript, adding to the functional complexity of the genome. Regulated alternative splicing may be used to create different proteins under different circumstances, allowing production of functionally related but distinct proteins and thus expanding the protein-coding potential of genes and genomes.
The identities of the genes that are being expressed in a biological sample at any given time and the amount of expression of those genes provide a gene expression profile for that sample. The gene expression profile is an indication of the status of that sample. For example, different tissue types will have different gene expression profiles reflecting the expression of different genes and differences in the spliced forms of individual genes. Differences in expression profile may also be observed between samples from the same tissue type when one sample is diseased. High-throughput methods to analyze and detect expression of alternative splice forms, characterization of alternative splicing, and regulation of alternative splicing are an important research focus.